The famously billowy condo tower planned for 150 Seaport Boulevard, on the Seaport District sites of the Whiskey Priest and the Atlantic Beer Garden, will open as an outpost of the St. Regis luxury brand, according to developer Cronin Development.

The firm reached a licensing deal with Marriott International, which is not itself involved in the development.

The tower is due to have 114 condos and to reach to 22 stories. A groundbreaking is expected this fall, with an opening scheduled for late 2020.

Such an opening will cap a long time of back-and-forth on the plans. The Conservation Law Foundation, an environmental group, agreed in January to drop a lawsuit against the project in exchange for $13.1 million in funding for a waterfront park, a public dock, and children’s programming.

The group had opposed Cronin’s (very expensive) plans on zoning grounds because of concerns about public access to the waterfront.

As it stands now, the future condos will come with access to a suite of St. Regis-branded luxury services, including concierge and butler service, and to amenities such as a swimming pool, a spa, a health club, a library, and what the developer is calling a golf-simulation room.

Then there’s the design of the building itself, courtesy of the late Howard Elkus of Elkus Manfredi. It is meant to evoke a billowy sail.

Stay tuned for sales (the other kind). Those are expected to launch in the fall.